What type of arthritis most commonly affects the hand?

Arthritis Affecting the Hand

Rheumatoid arthritis is the most common autoimmune arthritis that attacks the hand, characteristically affecting the metacarpophalangeal (MCP) joints, proximal interphalangeal (PIP) joints, and wrists in a symmetric pattern, while osteoarthritis is the most prevalent overall form of hand arthritis, typically targeting the distal interphalangeal (DIP) joints, PIP joints, and thumb base. 1

Rheumatoid Arthritis (RA)

Joint Distribution Pattern:

• RA characteristically involves the MCP joints, PIP joints, and wrists in a symmetric fashion 1, 2
• The DIP joints are rarely involved in RA, which helps distinguish it from osteoarthritis 2
• Hand involvement is typically the earliest manifestation of rheumatoid arthritis 2
• The disease affects approximately 1% of the population worldwide, with women having a lifetime risk of 3.6% compared to 1.7% in men 1

Clinical Presentation:

• Morning stiffness lasting 1 hour or longer is a cardinal feature that distinguishes RA from osteoarthritis 1, 3
• Symmetric polyarthritis with joint swelling, especially of the hands and feet 1
• Tender swelling on palpation with severe motion impairment, even before radiologic evidence of bone damage appears 2
• The inflammatory process is systemic and driven by autoimmune mechanisms 3

Critical Prognostic Implications:

• Life expectancy is shortened by 3 to 5 years, particularly in patients with extra-articular disease 1
• More than one-third of patients experience work disability; 80% are working at 2 years, declining to 68% at 5 years 1
• Early aggressive treatment with disease-modifying antirheumatic drugs improves patient functioning, quality of life, and survival 1

Osteoarthritis (OA)

Joint Distribution Pattern:

• OA primarily targets the DIP joints (Heberden nodes), PIP joints (Bouchard nodes), and thumb base (first carpometacarpal joint) 1
• The index and middle MCP joints may also be affected 1
• OA is the most common form of arthritis overall, affecting an estimated 302 million people worldwide 1

Clinical Presentation:

• Morning stiffness is mild and brief, typically lasting less than 30 minutes 3
• Pain occurs primarily with usage rather than at rest 1
• Symptoms are often intermittent and affect one or a few joints at a time 1
• Bony enlargement with or without deformity (lateral deviation, subluxation) at characteristic target joints 1

Pathophysiology:

• Primarily mechanical in nature, related to cartilage degradation and bone remodeling rather than systemic inflammation 3
• Limited inflammatory component that is localized to affected joints 3

Key Differentiating Features

Morning Stiffness Duration:

• RA: ≥1 hour (reflects systemic inflammation) 1, 3
• OA: <30 minutes (reflects mechanical factors) 3

Joint Pattern:

• RA: MCP, PIP, wrists; spares DIP joints 1, 2
• OA: DIP, PIP, thumb base; may involve index/middle MCP 1

Symmetry:

• RA: Symmetric involvement 1
• OA: May be asymmetric, affects specific joints 3

Other Arthritides to Consider

The differential diagnosis for hand arthritis includes 1:

• Psoriatic arthritis: May target DIP joints or affect just one ray
• Gout: Can superimpose on pre-existing osteoarthritis
• Hemochromatosis: Mainly targets MCP joints and wrists

Clinical Implications

For RA:

• Timely referral to rheumatology is critical, as early treatment with disease-modifying agents significantly improves outcomes and reduces disability 1
• The goal is complete disease remission or near-remission to prevent joint destruction and preserve function 1

For OA:

• Functional impairment in hand OA may be as severe as in rheumatoid arthritis and should be carefully assessed 1
• Patients with polyarticular hand OA are at increased risk for knee and hip OA (generalized OA) 1